BackgroundThe bacterial community present in the female lower genital tract plays an important role in maternal and neonatal health. Imbalances in this microbiota have been associated with negative reproductive outcomes, such as spontaneous preterm birth (sPTB), but the mechanisms underlying the association between a disturbed microbiota and sPTB remain poorly understood. An intrauterine infection ascending from the vagina is thought to be an important contributor to the onset of preterm labour. Our objective was to characterize the vaginal microbiota of pregnant women who had sPTB (n = 46) and compare to those of pregnant women who delivered at term (n = 170). Vaginal swabs were collected from women at 11–16 weeks of gestational age. Microbiota profiles were created by PCR amplification and pyrosequencing of the cpn60 universal target region.ResultsProfiles clustered into seven community state types: I (Lactobacillus crispatus dominated), II (Lactobacillus gasseri dominated), III (Lactobacillus iners dominated), IVA (Gardnerella vaginalis subgroup B or mix of species), IVC (G. vaginalis subgroup A dominated), IVD (G. vaginalis subgroup C dominated) and V (Lactobacillus jensenii dominated). The microbiota of women who experienced preterm birth (< 37 weeks gestation) had higher richness and diversity and higher Mollicutes prevalence when compared to those of women who delivered at term. The two groups did not cluster according to CST, likely because CST assignment is driven in most cases by the dominance of one particular species, overwhelming the contributions of more rare taxa. In conclusion, we did not identify a specific microbial community structure that predicts sPTB, but differences in microbiota richness, diversity and Mollicutes prevalence were observed between groups.ConclusionsAlthough a causal relationship remains to be determined, our results confirm previous reports of an association between Mollicutes and sPTB and further suggest that a more diverse microbiome may be important in the pathogenesis of some cases.Electronic supplementary materialThe online version of this article (10.1186/s40168-018-0502-8) contains supplementary material, which is available to authorized users.

The vaginal microbiome plays an important role in maternal and neonatal health. Imbalances in this microbiota (dysbiosis) during pregnancy are associated with negative reproductive outcomes, such as pregnancy loss and preterm birth, but the underlying mechanisms remain poorly understood. Consequently a comprehensive understanding of the baseline microbiome in healthy pregnancy is needed. We characterized the vaginal microbiomes of healthy pregnant women at 11–16 weeks of gestational age (n = 182) and compared them to those of non-pregnant women (n = 310). Profiles were created by pyrosequencing of the cpn60 universal target region. Microbiome profiles of pregnant women clustered into six Community State Types: I, II, III, IVC, IVD and V. Overall microbiome profiles could not be distinguished based on pregnancy status. However, the vaginal microbiomes of women with healthy ongoing pregnancies had lower richness and diversity, lower prevalence of Mycoplasma and Ureaplasma and higher bacterial load when compared to non-pregnant women. Lactobacillus abundance was also greater in the microbiomes of pregnant women with Lactobacillus-dominated CSTs in comparison with non-pregnant women. This study provides further information regarding characteristics of the vaginal microbiome of low-risk pregnant women, providing a baseline for forthcoming studies investigating the diagnostic potential of the microbiome for prediction of adverse pregnancy outcomes.

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Bifidobacteria colonize the human gastrointestinal tract, vagina, oral cavity and breast milk. They influence human physiology and nutrition through health-promoting effects, play an important role as primary colonizers of the newborn gut, and contribute to vaginal microbiome homeostasis by producing lactic acid. Nevertheless, the mechanisms by which bifidobacteria are transmitted from mother to infant remains in discussion. Moreover, studies have suggested that Bifidobacterium spp. have specializations for gut colonization, but comparisons of strains of the same bifidobacteria species from different body sites are lacking. Here, our objective was to compare the genomes of Bifidobacterium breve (n = 17) and Bifidobacterium longum (n = 26) to assess whether gut and vaginal isolates of either species were distinguishable based on genome content. Comparison of the general genome features showed that vaginal and gut isolates did not differ in size, GC content, number of genes and CRISPR, either for B. breve or B. longum. Average nucleotide identity and whole genome phylogeny analysis revealed that vaginal and gut isolates did not cluster separately. Vaginal and gut isolates also had a similar COG (Cluster of Orthologous Group) category distribution. Differences in the accessory genomes between vaginal and gut strains were observed, but were not sufficient to distinguish isolates based on their origin. The results of this study support the hypothesis that the vaginal and gut microbiomes are colonized by a shared community of Bifidobacterium, and further emphasize the potential importance of the maternal vaginal microbiome as a source of infant gut microbiota.

Amylases from Rhizopus oryzae and Rhizopus microsporus var. oligosporus were obtained using agro-industrial wastes as substrates in submerged batch cultures. The enzymatic complex was partially characterised for use in the production of glucose syrup. Type II wheat flour proved better than cassava bagasse as sole carbon source for amylase production. The optimum fermentation condition for both microorganisms was 96 hours at 30°C and the amylase thus produced was used for starch hydrolysis. The product of the enzymatic hydrolysis indicated that the enzyme obtained was glucoamylase, only glucose as final product was attained for both microorganisms. R. oligosporus was of greater interest than R. oryzae for amylase production, taking into account enzyme activity, cultivation time, thermal stability and pH range. Glucose syrup was produced using concentrated enzyme and 100 g L−1 starch in a 4 hours reaction at 50°C. The bioprocess studied can contribute to fungus glucoamylase production and application.